The invention relates to a baling press for large bales (large baler) for producing square high-density bales, in particular, agricultural crop bales, wherein the baling press is a self-propelled harvesting machine or a harvesting machine that is connected to a tractor and driven by the tractor. The baling press or baler picks up crop by means of pick-up and conveying devices and supplies crop to a pressing channel in which the crop is shaped to high-density bales. The bales are then tied in the longitudinal direction of the bale by several tying strands in order to ensure a permanent cohesion of the bales, wherein the tying strands for finishing the bales are connected to endless loops.
Such baling presses (balers) for large bales are known in various embodiments, sizes and drive variants.
However, on the market almost exclusively those balers are available that are connected to a tractor and are mechanically driven by the tractor wherein the compressed bales for permanent cohesion are preferably tied by several strands of twine that, before ejecting the bales from the baler, are knotted by means of a knotting device.
Square high-density bales are distinguished from round bales by a high uniform strength and stability and by their shape so that, inter alia, especially the transportation and storage conditions are very beneficial. In particular in the recent past, as straw is being used more and more as a raw material and an energy source and therefore must be transported often across large distances, the requirements put on baling presses for large bales have changed greatly. The profitability of stalk fodder harvesting and the profits from selling straw greatly depend on the harvesting, transporting and storage costs. Precisely based on this, special requirements are put on the baler technology. Highest tonnage in smallest space and particularly durable and shape-stable large bales are required even for crop that is cut to very short pieces or even crop that has been chopped.
Handling of such large and heavy bales does not present a limit as a result of professional loading technology, for example, wheel loaders or telehoist load luggers, used commonly nowadays. When producing such highly compressed and large size bales, one pushes on toward yet unreached dimensions with respect to the drive power and in particular with respect to the forces acting within the large balers. As a solution to these problems, in the publication DE 10 2007 015 649 A1, for example, a large baling press for producing extremely highly compressed bales is disclosed that, for reducing load on the tractor driving the baler, is provided with an additional hydraulic starter device for assisting in starting the machine.
Another limit encountered upon producing extremely highly compressed bales is tying of the bale for the purpose of its permanent safe cohesion.
Particularly in the field of stationary industrial baling presses for various materials, publications and attempts are known where an increased strength and stability is to be obtained in that other tying means, such as plastic strip or steel strip, and alternative joining methods using joining means such as gluing, welding are employed or additional tying means are used. In the field of large balers for agricultural crop, none of these solutions has however been accepted as preferable to knotting twine.
The high economic feasibility offered by the relatively minimal tying medium costs and short processing times and the processing safety of the knotting process, given the special conditions of a mobile harvesting machine, on the one hand, and the innocuous character of the twine knots in regard to risks to animal health and the environment, on the other hand, favor this method.
It is therefore the object of the present invention to improve a large baler for producing square high-density bales, in particular agricultural crop bales, in such a way that a permanent and shape-stable cohesion of the bales is ensured even for extreme increase of the pressing forces and thus of the strength and stability of the bales and for short-piece material to be pressed.